immunity

Minerals play a crucial role in maintaining the characteristics of the rumen environment in cattle, enhancing the fermentation process. Selenium, a rare yet essential mineral, is particularly important for improving immunity and reducing the incidence of certain diseases. By contributing to the structure of the enzyme glutathione peroxidase, selenium is vital for the antioxidant system. This study aimed to compare the effects of selenium-enriched probiotic supplements on the growth performance, feed intake, hematological parameters, and health status of suckling calves. For this purpose, a total of 80 newly born Holstein calves (35±1 kg) were selected immediately after birth and before the first milk feeding. They were randomly assigned to four treatment groups. Each treatment group received one of the following diets randomly: the first group served as the control group and received a starter without selenium supplementation. The second, third, and fourth groups received probiotics enriched with selenium at concentrations of 0.15, 0.30, and 0.45 ppm, respectively (SE0.15, SE0.3, and SE0.45). The feeding period, based on the dairy farming schedule and the feeding period for each treatment, was considered 75 days mixed in the starter. Throughout the experimental period, growth-related parameters such as average weight gain, height, average daily dry matter intake, as well as the health condition of the calves were evaluated by evaluating the health of the calves using the Wisconsin scoring index were recorded. The results of this experiment indicated that the SE0.45 treatment, which received a starter supplemented with 0.45 ppm selenium-enriched probiotic, exhibited a higher average weight compared to the control group (linear and quadratic, P<0.05). The experiment also demonstrated that selenium supplementation led to an improvement in average feed intake during the trial period, with SE0.45 treatment showing the best performance compared to the control group (linear and quadratic, P<0.05). According to the reported results in Table 7, the blood albumin concentration in the selenium-supplemented treatment groups was higher than that in the control group (linear, quadratic, and cubic, P<0.05). Additionally, the average concentration of glutathione peroxidase in the selenium-receiving treatment groups was higher than in the control group (linear, P<0.05). The results of this experiment indicated that adding selenium-enriched probiotics at levels of 0.30 and 0.45 ppm to the diet of suckling calves resulted in an increase in average height at the end of the experimental period compared to the control group (linear and quadratic, P<0.05). The daily height gain of the calves in the selenium-receiving groups was higher than the control group before weaning (linear, quadratic, and cubic, P<0.05). Microbial culture results of fecal samples indicated that the total bacterial count in the 0.45 ppm selenium-supplemented group was lower than that in the control group (linear, P<0.05). However, the population of Lactobacillus species in this treatment group was higher than in the control group (linear and quadratic, P<0.05). The addition of selenium to the diet of suckling calves not only affected height and weight gain but also improved the antioxidant system in the blood and enhanced the intestinal microflora conditions of the calves. Based on the regression results obtained, the optimal selenium supplement dose in the diet of suckling calves until weaning was calculated to be between 0.11 to 0.41 ppm. The average optimal doses obtained for all significant traits are equivalent with 0.3 ppm on selenium in the supplement.

The use of growth-promoting antibiotic substitutes in commercial broiler farming is mainly due to the development of resistant bacteria. The use of growth-promoting antibiotics in mother hens may have important consequences, one of these effects being the reduction of the effect of antibiotics in the offspring whose parents received these antibiotics (McDonald 1995, Ghasemian and Jahanian 2016). One of the proposed alternatives to growth-promoting antibiotics are prebiotics, which include non-starch polysaccharides that are not digested in the digestive system, including fructo-oligosaccharides, galactoligosaccharides, beta-glucan, mannan oligosaccharides, etc. The main components of the yeast wall are beta-glucans and mannan oligosaccharides. which are of special importance in feeding broiler breeders because it not only changes the intestinal microflora for the benefit of the animal, but also has properties to modulate the immune system (Arsi et al. 2015). The use of cell wall yeast promotes the growth of beneficial bacteria throughout the digestive tract. Among the different probiotic species, lactobacilli and bifidobacteria use the yeast cell wall the most and grow the most when it is used (Liu et al. 2018) and also have a greater contribution to poultry health (baurhoo 2007b). Increasing the number of useful cells in the intestine reduces the number of harmful bacteria. On the other hand, the mannan present in the yeast cell wall reduces the binding of Gram-negative bacterial pathogens such as salmonella and E-coli to the intestinal epithelial cells by binding type one fimbriae. Bacteria colonize the intestine without attachment and colonization, and it is directly related to the strengthening of the animal's immune system (baurhoo 2007b). It has also been reported that the mannan fraction present in the yeast cell wall has anti-adhesion activity against Campylobacter jejuni (Ramirez-Hernandez et al., 2015; Corrigan et al., 2017).

In order to investigate the effect of different cell wall yeast levels of Saccharomyces cerevisiae in feeding broiler breeders, cell wall yeast product was prepared from Chitika Company. For this purpose, 100 broiler breeder and 25 broiler roosters (Ross 308) 54 week olds were prepared and randomly distributed in 5 treatments and 5 replications with 25 experimental units (4 broiler breeder and one rooster in each unit). The experimental treatments included 1- the control treatment (without Saccharomyces cerevisiae yeast cell wall) and treatments 2 to 5 containing 0.5, 1, 1.5 and 2 g/kg of Saccharomyces cerevisiae yeast cell wall in feed respectively. The duration of the experiment was 12 weeks, which was divided into 3 periods (age 54-57, 58-61, and 62-65 weeks), and the birds had free access to water and food during the entire experiment. Room temperature, lighting duration and other management items were based on the standard of the strain guide (birds had the same amount of feed). The experiment was divided into three periods of four weeks according to the different stages of the birds' production, and for this purpose, at the end of the 4th, 8th and 12th weeks, the birds were weighed and the average weight of each group was reported. The eggs of all experimental treatments were counted and collected separately in the whole period. In order to determine production performance, production percentage and average egg weight were measured and calculated daily in the entire period and the results were reported. In order to check the quality characteristics of eggs, at the end of the 8th and 12th week, 2 eggs were randomly selected and evaluated from each replication, and the average of these two weeks was reported in the results of this study. The resistance of the egg shell was measured using a Japanese resistance measuring device with specifications (Co., Ltd., Tokyo, Japan Robotmation) in which the eggs were placed vertically and the egg cracked due to the applied force and the applied force It was measured in kilograms per square centimeter.

The experimental treatments had no significant effect on the weight changes of broiler breeders. The results showed that the experimental treatments had significant effects on the percentage of egg production in all three test periods. In the first period of the experiment, the group fed with 1.5 and 2 g/kg with 63.97 and 63.54 percent egg production had a significant difference compared to the control group which had 62.35 percent production. In the second period (age 58-61 weeks), the group fed with one g/kg of Saccharomyces cerevisiae yeast had a significantly higher percentage of egg production than the control group. In the third period, the groups receiving Saccharomyces cerevisiae yeast had a significantly higher percentage of egg production than the control group. Different levels of Saccharomyces cerevisiae yeast did not have a significant effect on shell resistance and thickness in broiler breeders compared to the control group. The test results show the effect of treatments containing 1, 1.5 and 2 g/kg of Saccharomyces cerevisiae cell wall causing a significant reduction in the number of broken eggs. The use of levels of 1, 1.5 and 2 g/kg of cell wall yeast in the diet caused a significant increase in the antibody titer of Gambro virus in broiler breeders during the experimental period.

The results of this study showed that in the three defined experimental periods of 54-57, 58-61 and 62-65 weeks, experimental treatments had no significant effect on body weight changes. Treatments containing 0.5, 1, 1.5 and 2 g/kg of Saccharomyces cerevisiae wall yeast significantly increased the percentage of eggs produced compared to the control group, as well as the effects of decreased production due to aging in the feeding groups. It was less with yeast cell wall. Experimental treatments had no effect on average egg weight, egg resistance and shell thickness. The percentage of deformed and broken eggs in the groups receiving 1, 1.5 and 2 g/kg of cell wall yeast significantly decreased compared to the control group. In general, according to the results obtained from this research, it can be said that the use of commercial yeast Saccharomyces cerevisiae has favorable effects and also the best level used is 1 g/kg of feed.

The present study was conducted to evaluate the effect of supplementing egg yolk multi-antibodies against diarrhea pathogens on growth performance, hematological parameters, and feces microbial culture of Holstein suckling calves. 48 calves (male and female) were randomly assigned to three treatments and kept individually from 1 to 28 days of age. The treatments included the group fed with immunopro supplement (containing egg yolk multi-antibody and various probiotics, prebiotics, vitamins, and electrolytes) (IP), the positive control group containing all components of the treatment group without multi-antibody (C+) and the negative control group (C-). Feed intake was recorded every day, body weight and Skeletal growth parameters of calves was recorded every seven days, hematological parameters were measured on day 1 and 28, and feces microbial culture parameters were measured on day 28. The use of IgY supplements increased body weight, daily weight gain, dry matter intake, and feed efficiency (P < 0.05). Skeletal growth parameters (withers height, hip height, hip width, and Heart girth), hematological parameters, and feces microbial culture parameters were not affected by the experimental treatments. The use of IgY supplement decreased feces score, duration of diarrhea, and body temperature (P <0.05). The results suggested that the consumption of IgY against diarrhea pathogen's for up to 28 days promoted the immunity and health of Holstein's suckling calves.

 Optimal nutrition occurs only when poultry efficiently use the nutrients in the feed for growth, health, reproduction and survival. Vitamins should be present in sufficient amounts in the diet due to their vital functions in the animal's metabolism and the optimal utilization of other nutrients.

Five hundred one-day-old 308 Ross strain chicks (male and female) were distributed in a completely randomized design with 5 treatments, 5 replications and 20 chicks per replication. Dietary treatmets are included five levels of vitamin supplementation: 1) control (100% recommended values of strain Ross 308 catalog), 2 to 5) 90%, 80%, 70% and 60% recommended values. During the 42 days of the experimental period, performance was recorded at the end of each period (ages 10, 24 and 42 days). Evaluation of humoral immune response was performed using SRBC injection at 35 days of age. Cellular immune response was assessed at 37 days of age by hypersensitivity test. At 42 days of age, ten birds per treatment were bled to count white blood cells and then the birds were slaughtered, and the relative weights of different parts of the carcass were measured.

The suggested level of 80% vitamin supplement had no significant effect on performance including feed intake, FCR, survival percentage and production index (p<0.05). By reducing the level of vitamin supplement, the length of jejunum and the percentage of wings and spleen decreased in the experimental treatments (p<0.05), but the percentage of carcass and other components were not affected (p>0.05). Antibody titer in response to SRBC injection, cellular immune response and the number of white blood cells were not affected in level of 80% vitamin supplement, although the level of 80% vitamin supplement significantly reduced IgG titer and heterophil percentage (p<0.05).

In general, the results showed that it is possible to reduce the level of vitamins in the diet of broiler chickens by 20% without negatively affecting the performance and responses of cellular and humoral immunity.

Effect of using eucalyptus (Eucalyptus SPP) leaf chloroform oral extract (EE) and black pepper (Piper nigrum) powder (BP) in diet on growth performance, carcass traits, blood parameters and microbial populations of intestine and syrinx was investigated in a 42 days trial with 160 Cobb 500 day-old chicks divided into four treatments and four replicates as a completely randomized design. The treatments were 1- basal diet (control), 2- basal diet and adding 0.1 % EE solution in drinking water, 3- diet having 0.2% BP, and 4- diet having 0.2% BP and 0.1% EE solution in drinking water. Over the study, feed intake of chickens consumed oral EE or BP in diet and/or the combination of them was lower than chickens in control group (P<0.05). Weight gain and feed conversion ratio of chickens were not affected by the treatments. Oral EE resulted in greater percentile lungs weight and lower heart and abdominal fat weights in chickens (P<0.05). Using oral EE or BP in diet and/or the combination of them caused a significant decrease in serum concentrations of glucose, cholesterol and uric acid in chickens (P<0.05). Hematological parameters of chickens were not affected by the experimental treatments. Chickens consumed oral EE or BP in diet and/or the combination of them showed a significant lower intestinal E-coli population than control birds (P<0.05). Furthermore, using oral EE caused a decrease in Mycoplasma population of broilers Syrinx (P<0.05). The results showed that using oral EE leads to lowered abdominal fat and microbial populations of intestine and syrinx while adding BP in diet leads a decrease in microbial populations of intestine in broiler chickens.

The effects of valine supplementation on performance, immunity and behavioural indices of broiler chickens under heat stress condition was evaluated. Total of 420 male and female Ross-308 broiler chickens were allocated to 6 treatments with 5 replicates in a completely randomized design. Experimental groups were as fallows: positive control (fed basal diet and reared under Ross-308 recommended rearing temperature), nagative control (fed basal diet and reared under heat stress (HS)), and four treatment groups fed basal diet supplemented with 5, 10, 15 and 20% valine above the Ross-308 valine recommendation and reared under HS. Heat stress significantly decreased feed intake, body weight and European production efficiency factor (EPEF), antibody titer against NewCastle, lymphocyte percentage, serum total protein concentration and alkaline phosphatase and lactate dehydrogenase activities and increased heterophile percentage, heterophile to lymphocyte ratio, rectal temperature and tunic immobility of broiler chickens (P< 0.05). Supplementation  of5% valine improved BW of broiler chicken at the end of grower and BW and EPEF at the end of total period. Addition of  10% valine increased relative weight of breast and thigh muscle and 15 and 20% valine supplementation increased lymphocyte and decreased heterophile percentage as compared to control group (P< 0.05). In conclusion, 5% valine supplementation improved final body weight and feed convertion ratio of heat-stressed broiler chikens and 15 and 20% valin inclusion improved blood immune cell percentages but had no effect on humoral immune response and tunic immobility test of HS broiler chickens.

To evaluate the effect of hydroalcoholic extract of Scrophularia striata (SSE), vitamin E, vitamin C, and selenium on performance, blood parameters, and immune response of broilers under heat stress conditions, an experiment was performed using 350 one-day-old male broilers (Ross 308) in a completely randomized design with seven treatments and five replicates (10 chickens per replicate). Experimental groups were a group under normal environmental conditions (negative control), a group under heat stress (positive control), and other groups under heat stress and fed with the diet supplemented with 200 ppm vitamin E, 500 ppm vitamin C, 0.3 ppm selenium, or 200 and 400 ppm SSE. From day 1 to the end of the breeding period, a temperature of 34 ± 2 °C was applied to create heat stress for 8 h (10 am to 6 pm). The results showed that all treatments improved (P<0.05) body weight gain, feed conversion ratio, performance index, heterophil to lymphocyte ratio, total and IgG titers against sheep red blood cells, and cellular immunity (toe web swelling skin in response to phytohemagglutinin injection), and the best performance was observed in the negative control, high SSE and vitamin E, respectively. All experimental treatments, except for low SSE and selenium treatments, increased blood lymphocytes and potassium compared to the positive treatment (P<0.05). In general, the inclusion of 400 ppm of SSE in the diet had a beneficial effect on growth performance, blood parameters, and immune response during heat stress.

This study aimed to compare experimental treatments containing Leek extract with Phosphoflavomycin growth-promoter antibiotic using 160 Ross-308 day-old chicks in a completely randomized design manner with 4 experimental treatments, 4 replicates, and 10 chicks per replicate for 42 days. Treatments consisted of 1) control group (basal diet); 2) basal diet with Phosphoflavomycin antibiotic growth promoter (0.04%); 3) basal diet with 0.3% Leek ethanolic extract; and 4) basal diet with 0.5% Leek ethanolic extract (P≤0.05). Feed intake, feed conversion ratio, visceral weights, antibody production against Influenza and Newcastle diseases, biochemical parameters of Glucose, Cholesterol, Triglyceride, HDL, LDL, Albumin, Total Protein, and AST were not affected by different treatments (P≥0.05). However, both groups fed Leek extract (0.3% and 0.5% of diet) increased serum levels of liver enzymes of ALT and ALP significantly, compared with Phosphoflavomycin growth promoter (P≤0.05). Based on the findings of the current study, it can be concluded that consumption of Leek ethanolic extract (0.5% of the diet) showed a significant enhancement on the body weight of broilers, with no impact on visceral weights, immune status, and blood biochemical indices.

This study was conducted to investigate the effects of anti-stress feed additive containing probiotic Protexin®, vitamin C and betaine in three commercial broiler strains on immune responses, some blood parameters and oxidative stability of breast muscle under heat stress conditions. A total of 720 one-day-old broiler chicks were used in a completely randomized design as a 2×3 factorial arrangement consisting 2 levels of additive (with and without) and three broiler strains (Arbor Acres, Ross 308 and Cobb 500) with 6 treatments, 4 replicates and 30 birds in each replicate. The birds were exposed to heat stress (37 °C) for 8 hours daily from 22 to 42 days of age. In addition of performance parameters, humoral immune response was measured by intravenous administration of 5% sheep red blood cell (SRBC) suspension and primary and secondary antibody titers were determined. At 42 day of age, blood samples were collected to measure blood serum parameters including total protein, cholesterol, triglyceride, HDL and LDL. The heterophile to lymphocyte ratio and also glutathione peroxidase and super oxide dismutase enzyme activities were evaluated at 42 day of age. Among the evaluated parameters, only LDL concentration was affected by experimental strains (p < 0.05) and the minimum serum LDL concentration was observed in Arbor Acres strain. Generally, the strain and feed additive used in this experiment had no significant effect on immune response and breast muscle oxidative stability of heat-stressed broilers.

Nowadays, there is an increasing interest to use organic compounds in broiler chicken diets instead of antibiotics and other feed additives may cause deleterious effects on the poultry products consumers. Using medicinal plants have different effects on broiler life such as improving feed efficiency, augmentation of immunity, producing more desirable carcass and so on. The goal of this study was to investigate the effect of adding coneflower and thyme alcoholic extracts to diet on performance, carcass characteristics, internal organs weights and also some blood and immunity parameters of broiler chickens.

One hundred-sixty 1-d-old chickens (male and female) were randomly divided into four treatment groups with four replicates in each, and reared for 42 days. The treatments were: 1- control (basal diet formulated according to Cobb500 nutrients recommendation), 2- adding 0.2% thyme extract into basal diet, 3- adding 0.2% coneflower extract into basal diet, and 4- adding 0.2% of thyme+ 0.2% of coneflower extracts into the respective basal diets; starter (1-10 d), grower (11-23 d) and finisher (24-42 d) that were fed to the birds from the beginning. Experimental plants extracts were collected via UV-extraction method by ethanol followed by the rotary evaporation to eliminate the diluent. All the feeding and vaccination programs of chickens were in accordance with Cobb500 commercial strain recommendations. Feed intake, weight gain and feed conversion ratio of chickens were weekly recorded. At the end of the study, one bird of each replicate was slaughtered for carcass analysis and blood sampling. Blood parameters were assayed via  spectrophotometer. Carcass parts and internal organs weights were expressed as a percent of carcass weight. The antibody titers against Newcastle and
Influenza diseases were assayed. Data were analyzed as a completely randomized design and the means comparison was performed by least significant different test.

Results showed that the effect of treatments on the amounts of feed intake and weight gain of chickens over the study. Feed conversion ratio of chickens was significantly affected by the treatments where the lowest was observed in control group and the highest in coneflower group. Carcass traits (the weights of empty carcass, breast, thighs, abdominal fat and back) and internal organs weights (liver, heart, lungs, intestines and gizzard) were not affected by the treatments. The weights of body organs are basically affected by genetic potential that the used chickens were very close in this sight of view, and weight gain also among groups was not significantly different. Effect of treatments on antibody titers against Newcastle and influenza was significant. The lowest antibody titer against Newcastle and the highest against influenza were observed in thyme group. Both of coneflower and thyme were showed having stimulatory effect on antibody production in poultry, but the different effects observed in the present study may be due to the epidemic of
diseases and also the hygienic conditions of the farm. Adding coneflower and thyme into the diet increased the bursa of fabricius weight of chickens than the control, but it had no significant effects on spleen weight. It should be mentioned that the chickens in the present study were vaccinated according to the provider company recommendations and also a coccidiostat compound was used in the diet that they together can obstruct or interrupt on the expected beneficial effects of coneflower and thyme on immune parameters. Adding thyme and coneflower into the diet caused a marked decrease in blood lipids concentrations. One of the desired properties of medicinal plants is lowering the blood’s and carcass’s lipids that was observed in the present study. It is reported that these plants have some components suppressing the lipids synthesis in liver and also other ones effect on lipase enzymes activity in tissues. The treatments had no significant effects on the hematological parameters of chickens. Whereas there were no significant differences in the amount of daily feed intake and weight gain of chickens and also all of the environmental conditions for chicken were the same, therefore none of hematological parameters were affected by the treatments.

Generally, adding coneflower and thyme extracts into the diets of chickens had not significant effects on their growth performance in the overall period of the experiment and carcass traits as well. Using coneflower and thyme extracts in broilers diets has a booster effect on the antibody titer against influenza, while no positive effects were observed for Newcastle disease. Adding coneflower and thyme extracts into the diet of chickens prominently decreased the all types of blood lipids. No synergistic effects were observed between coneflower and thyme extracts wherever they had a significant effect on assayed parameters.

In order to evaluate the effect of different levels of corn gluten feed on performance, immune responses, intestinal morphology and some blood serum biochemical parameters of broiler chickens, an experiment was conducted using 500 male Ross 308 broiler chickens in a completely randomized design with four treatments, five replicates and 25 birds per replication. The experimental treatments included levels  of zero (control), 2.5, 5 and 7.5 percent corn gluten feed in the diet which fed to broilers from 15 to 42 days of age. The results showed that dietary inclusion of corn gluten feed up to 7.5 percent had no significant effect on average weight gain, feed intake and feed conversion ratiocompared to control treatment. Also, jejunal morphological indices and blood biochemical parameters including triglyceride, cholesterol, albumin, phosphorus and alkaline phosphatase concentrations, livability, European broiler index and feed cost per kg of weight gain were not affected by dietary treatments. Antibody titer in response to sheep red blood cell (SRBC) injection was higher in treatment containing 2.5 percent corn gluten feed comparing to other treatments (P<0.05). Based on the obtained results, corn gluten feed can be included in grower and finisher diets of broilers (15 to 42 days of age) up to level of 7.5 percent without any adverse effect on performance.

The effects of high stocking density and threonine (Thr) supplementation on performance and immunity in broiler chickens was evaluated. In this experiment 495 male Ross-308 broiler chickens were allocated to 4 treatments with 5 replicates in a completely randomized design. The dietary treatment consisted of: 1) basal diet as control with low density (10 birds/m2), 2) high density group (15 birds/m2 which fed basal diet) and 3 and 4) high density group which fed diet containing 10 and 20 percent Thr higher than requirment, respectively. The results showed that high stocking density decreased feed intake, body weight and feed conversion ratio at different period of production and increased European production efficiency factor (EPEF). Thr supplementation also reduced growth performance parameters (P < 0.05).Dietary treatments deseased antibody titer against NewCastle, but avian influenza virus, cell mediated immunity against phytoheamaglutinin, blood metabolites, blood cell count, and serum spartat aminotransferase and malondialdehyde concentration did noy change significantly. Serum alanine aminotransferase concentration in broiler chickens fed diet containing 20 percent Thr higher than requirment was higher than the others (P < 0.05). In conclusion, under the condition of this study (15 birds/m2), Thr supplementation (both of the levels) did not improved broiler chickens performance and immunity and more research is needed in this subject.

The purpose of this experiment was to compare the effects of essential oils blend with probiotic and Flavomycin as antibiotic growth promoter on humoral immunity, meat quality, and some blood parameters in broiler chickens. A total of 288 day-old Ross 308 strain broiler chicks based on a completely randomized design was allocated to four treatments with four replicates and 18 birds in each replicate. Treatments were included: 1) control (a basal diet containing corn and soybean meal without additive), 2) basal diet + 150 mg/ kg essential oils, 3) basal diet +200 mg/ kg probiotic Gallipro®, and 4) basal diet +150 mg/ kg Flavomycin. In order to evaluate humoral immune response, antibody titers of sheep red blood cells (SRBC) were measured by hemagglutination method at 26 and 33days. In order to evaluate blood parameters and meat quality, two birds per replicate were slaughtered and blood samples were collected.  Humoral immune response was not significantly different between groups (P >0.05). Redness index (a*) in thigh muscle and pH of breast muscle 24 h after slaughter decreased (P<0.05) in treatments 2 and 3 compared with 1 and 4. Plasma concentration of HDL was significantly lower by 4 treatment than other groups (P < 0.05). Generally, the results of this study showed that dietary supplementation of essential oils blend, probiotic and Flavomycin to broiler chickens did not affect immune response of the birds, but pH of meat was improved after slaughter. In addition, Flavomycin supplementation of diet had a negative effect on blood HDL concentration.